Problems syncing this morning : invalid block, please help

[gabrio81]

hi there guys,

I just launched Core earlier this morning - usually things are very fast on my SSD but for some reason it's stuck, connections with the little 4 dots come and go and it's still stuck on "Unknown, syncing headers 676880 99.8%"

I didn't have any crashes or unclean shutdown, all perfectly normal, no odd restarts or cable unplugs on the hdd.

I tried to shut it down cleanly once then relaunch and same thing. it's about 30 minutes there now - usually very fast to sync like 10-15 mins max.

Is there something going on the network?

I am syncing monero core and that one is going well.

On the log i can see several of these:

2021-04-06T09:50:14Z Disconnecting and discouraging peer 163!
2021-04-06T09:50:23Z New outbound peer connected: version: 70016, blocks=677993, peer=181 (full-relay)
2021-04-06T09:50:35Z New outbound peer connected: version: 70015, blocks=677993, peer=182 (full-relay)
2021-04-06T09:50:44Z ERROR: AcceptBlockHeader: block 0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7 is marked invalid
2021-04-06T09:50:44Z Disconnecting and discouraging peer 181!
2021-04-06T09:50:45Z ERROR: AcceptBlockHeader: block 0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7 is marked invalid
2021-04-06T09:50:45Z Disconnecting and discouraging peer 182!
2021-04-06T09:50:46Z New outbound peer connected: version: 70015, blocks=677993, peer=184 (full-relay)
2021-04-06T09:50:58Z New outbound peer connected: version: 70015, blocks=677993, peer=188 (full-relay)
2021-04-06T09:51:43Z New outbound peer connected: version: 70016, blocks=677993, peer=193 (full-relay)
2021-04-06T09:51:50Z ERROR: AcceptBlockHeader: block 0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7 is marked invalid
2021-04-06T09:51:50Z Disconnecting and discouraging peer 188!

Apparently this block is marked invalid:

2021-04-06T09:29:32Z ERROR: AcceptBlockHeader: block 0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7 is marked invalid throughout

please let me know

thanks,
Gabrio

[1714058113]

1714058113

[ranochigo]

Go to Window>Console and type this:

Code:

reconsiderblock 0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7

If it doesn't solve the problem, then your database is corrupted and you need to reindex. It can happen due to hardware failures; would be good if you could test your RAM for any inconsistencies.

[gabrio81]

thanks, this is what he spit back to me:

12:46:15

null

is that the intended output?

best,
Gab

[gabrio81]

Go to Window>Console and type this:

Code:

reconsiderblock 0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7

If it doesn't solve the problem, then your database is corrupted and you need to reindex. It can happen due to hardware failures; would be good if you could test your RAM for any inconsistencies.

argh ((( everything is perfect here and last sync was without errors, so that's odd.

something similar happened other times when say i unplugged the hard disk without disconnecting or pulling the cable by mistake etc.

this time not. everything was always done proper.

[gabrio81]

more connections now - 15 and i see the 4 little arrows filled... in log i have now:

2021-04-06T10:46:15Z UpdateTip: new best=0000000000000000000b818d87315f69398aa6ba886d869f8c403a41f509e7f7 height=676881 version=0x20000000 log2_work=92.771642 tx=629219354 date='2021-03-29T18:50:42Z' progress=0.996321 cache=19.4MiB(144694txo)
2021-04-06T10:46:17Z New outbound peer connected: version: 70015, blocks=677998, peer=789 (full-relay)
2021-04-06T10:46:18Z New outbound peer connected: version: 70015, blocks=677998, peer=791 (full-relay)
2021-04-06T10:46:30Z New outbound peer connected: version: 70015, blocks=677998, peer=794 (full-relay)
2021-04-06T10:47:09Z New outbound peer connected: version: 70015, blocks=677998, peer=800 (full-relay)
2021-04-06T10:47:11Z New outbound peer connected: version: 70015, blocks=677998, peer=801 (full-relay)
2021-04-06T10:47:38Z New outbound peer connected: version: 70015, blocks=677998, peer=805 (full-relay)
2021-04-06T10:47:45Z New outbound peer connected: version: 70015, blocks=677998, peer=806 (full-relay)
2021-04-06T10:47:45Z New outbound peer connected: version: 70016, blocks=677998, peer=807 (full-relay)
2021-04-06T10:47:47Z New outbound peer connected: version: 70015, blocks=677998, peer=808 (full-relay)
2021-04-06T10:47:47Z New outbound peer connected: version: 70016, blocks=677998, peer=809 (full-relay)

no more notes about the block being invalid, let's give it some time. thanks for now....

YEEEEEEEEEEE it picked up blocks now!!! CPU is flying again thank youuuuuuuu

[ranochigo]

null

is that the intended output?

Yup. Great that it is working for you!

Nonetheless, if you have the time, you can try some utility to test your memory, CPU and your disk and see if there are any defects in them. Blocks shouldn't be invalidated without the user specifically marking it or if there is a block corruption. It has worked once previously but it didn't for another and I didn't manage to get that user to run any tests.

[gabrio81]

well all i can think of is that i keep BTC core on an external fast ssd, i will check that one for corruption, etc once finished

thanks again

[gabrio81]

it's fully synced now. closed BTC.

checked disk, ran a CHKDSK no errors, ran a disk check from win10 also all good.

launched BTC core again, fully working this time instantly.

[NotATether]

checked disk, ran a CHKDSK no errors, ran a disk check from win10 also all good.

Note that if you want to test your RAM you would download memtest86 and make a ISO image of it to boot from.

On Windows it is even easier to test your memory, you just click on the Search magnifying glass at the bottom left and type "Windows Memory Diagnostic" or "mdsched.exe" and launch the resulting program that appears. Then you can either tell it to restart immediately or wait until the next restart to run the memory test.

Some Linux live DVDs  already have memtest86 and display a Test Memory entry in the boot menu so you can just use that instead if you have one lying around.

[nc50lc]

checked disk, ran a CHKDSK no errors, ran a disk check from win10 also all good.

I saw that you've already encountered the same issue before: Core 0.20.0 sync stuck on a block, please help, has there been a fork?
On August 2 last year, experiencing the same issue twice is a bit concerning.

Are you perhaps using Debian OS? Because there was an old closed issue, but not closed because of a PR that fixed it, but for using par=1 to use only one thread for script verification that seems to effectively fix the issue.
Issue link: /bitcoin/bitcoin/issues/2726

[gabrio81]

i just did extended mem testing all night over 8 hours, plus basic and standard testing, all no errors.

and frankly, i never never get any blue screen here which is usually RAM, since i installed this and i have a high performance Ram.

yeah you are right, you are like Sherlock Holmes hehe looks like i had that problem before.

and no, i am on Win10 64x.

only thing i can think of is that i have BTC core on ext usb 3.1 SSD drive (at that time it was not SSD tho). this one is faster now.

[ranochigo]

only thing i can think of is that i have BTC core on ext usb 3.1 SSD drive (at that time it was not SSD tho). this one is faster now.

Without any information about what went wrong when Bitcoin Core invalidated it, it'll be hard to pinpoint the problem especially if your hardware is doing fine.

However, I'll consider USB external drives far less reliable than SATA ones. The controllers that I've had for my drives were not exactly the best though they were fairly expensive and well known. Bitcoin Core tends to magnify the problems associated with them due to the nature of the program and how it interacts with the disk. Assuming that your data directory is on the external SSD.

[gabrio81]

Yes indeed but i find it better and safer having the data stored on an external hard disk, although the occasional problem like this may occur.

[HCP]

Do you happen to be using an AMD ryzen 3000 or 5000 series CPU on one of the 4xx or 5xx series chipset motherboards (B450/X470/B550/X570)? There have been issues surrounding USB and AMD Ryzen 400/500 series motherboards causing random dropouts of USB connectivity...

Refer: https://www.tomshardware.com/news/amd-suggest-possible-fixes-for-usb-connectivity-issues

[gabrio81]

nope, i am using an asus S15 Vivobook slightly pimped

[gabrio81]

hello,

resurrecting a thread of a little while ago, it happened again i had to launch a "reconsiderblock" was wasn't syncing.. are these rogue blocks or something?

i mean i don't mind doing this but ideally shouldn't happen right? then picked up again and works now again. just like last time.

didnt have any unclean shutdowns, etc

thanks

[HCP]

There aren't rogue blocks as such... so the issue is likely data corruption due to an issue with hardware.

Given the length of time between issues... it seems like it is a transient issue, which can be a real pain in the arse to diagnose From your previous post, you're using a laptop, with an external drive is being used to store the block data. Is it a USB powered drive, or does it have a separate power adapter?

If USB powered, it's possible that you might be experiencing some sort of intermittent power delivery issue with the laptop's USB port that is causing the data corruption. Again, given that this isn't a constantly occurring issue, it will likely be very very difficult to reliably replicate this issue to try and figure out the exact conditions that cause it to happen.

For instance, it's possible that adding/removing other USB devices might do it... or the system trying to put devices to sleep or low power mode etc.

Have you tried a different USB port on your laptop? If that doesn't solve it and you continues to get these invalid blocks on a relatively regular basis, you might need to try and power the device with an external power adapter using a Y-Cable etc and see if that helps.

[pooya87]

are these rogue blocks or something?

The only way to know what goes wrong that rejected this block is to have the full block with 0000...09e7f7 hash as it was the first time your node saw it and see why it was rejected in first place.
The error message saying "is marked invalid" is not enough information since the hash belongs to a real bitcoin block.

[ranochigo]

hello,

resurrecting a thread of a little while ago, it happened again i had to launch a "reconsiderblock" was wasn't syncing.. are these rogue blocks or something?

i mean i don't mind doing this but ideally shouldn't happen right? then picked up again and works now again. just like last time.

didnt have any unclean shutdowns, etc

thanks

They aren't. If anyone were to send you an invalid block, your client would just reject it and follow the longest chain. This isn't the case because the block is valid and it is also in the longest chain. That is why you're always stuck at synchronization.

It shouldn't happen at all. This means that Core wasn't able to validate the block when it first saw it, perhaps due to it being unable to validate certain data within the block. But yeah, as I said might be your USB controller which can't be fixed unless you swap it out or use the internal drive.

[gabrio81]

thanks guys - on the hard disk i don't completely agree with that, as in the USB port of the laptop, i think is something else, read below:

Now, what i think it could be is the fact that i am running simultaneously also 2 other crypto CORES which will be remain unknown for now so it's very well possible that sometimes slips out.

Power delivery issue i don't think so, it's plugged straight to the usb-c to the laptop and always with AC on.

I will try running only BTC core alone when i do the sync and not the 2 other chains as well - they never had this issue, though.

with that exclude command executed i can then transact, everything works normally, and if i need to do it ever 2-3 months is not a huge deal.

As i said, i don't think that's an issue with the USB port of the laptop but due to the setup i have - where i basically do my weekly sync for 3 CORE blockchains together (not always but quite often because the machine and the SSD is capable enough), that i think could lead to some minimal data corruption with the amount of I/O happening at the same time. And given that BTC is the "biggest" whale, i will let it go on his own only now.

time will tell

thanks again,
Gabrio